11,047 research outputs found
Dienes, Louis -- 1939-42 -- Correspondence, Individual -- letter, 1941-10-17
No full textLetter from Dienes, Louis to Sabin, Albert B. dated 1941-10-17.Sabin Collection Fair Use Policy</a
Dienes, Louis -- 1939-42 -- Correspondence, Individual -- letter, 1939-06-02
No full textLetter from Dienes, Louis to Sabin, Albert B. dated 1939-06-02.Sabin Collection Fair Use Policy</a
Organolanthanide-Catalyzed Cyclization/Boration of 1,5- and 1,6-Dienes
No full text1,5- and 1,6-Dienes undergo a cyclization/boration reaction in the presence of a catalytic amount of Cp*2Sm·THF. The resulting organoboranes
can be oxidized to the corresponding primary cyclic alcohols using standard conditions
A Dual CuH- and Pd-Catalyzed Stereoselective Synthesis of Highly Substituted 1,3-Dienes
No full textConjugated
dienes are versatile building blocks and prevalent substructures
in synthetic chemistry. Herein, we report a method for the stereoselective
hydroalkenylation of alkynes, utilizing readily available enol triflates.
We leveraged an in situ-generated and geometrically
pure vinyl-Cu(I) species to form the Z,Z- or Z,E-1,3-dienes in excellent
stereoselectivity and yield. This approach allowed for the synthesis
of highly substituted Z-dienes, including pentasubstituted
1,3-dienes, which are difficult to prepare by existing approaches
Visszatekintés : Életmű interjú Dienes Istvánnal
No full textDienes István szakmai életútja, amely a mérhető információgazdaság megfogalmazásáig vezette
Copper-Catalyzed Asymmetric Reductive Allylation of Ketones with 1,3-Dienes
No full textA catalytic chemo-, regio-, and enantioselective
allylation of
ketones with 1,3 dienes in the presence of (R,R)-Ph-BPE ligated Cu catalyst and hydrosilane is presented.
This method provides a straightforward and alternative avenue to synthesize
chiral homoallylic tertiary alcohols with 1,3-dienes as the latent
allylic nucleophiles and avoids the traditional reliance on stoichiometric
quantities of allylmetal reagents. This transformation proceeds under
very mild conditions and displays good functional group tolerance
and could be performed on a gram-scale
Rhodium-Catalyzed Hydrofunctionalization: Enantioselective Coupling of Indolines and 1,3-Dienes
No full textWe communicate a strategy for the
hydrofunctionalization of 1,3-dienes
via Rh-hydride catalysis. Conjugated dienes are coupled to nucleophiles
to demonstrate the feasibility of novel C–C, C–O, C–S,
and C–N bond forming processes. In the presence of a chiral
JoSPOphos ligand, hydroamination generates chiral allylic amines with
high regio- and enantioselectivity. Tuning both the pKa and steric properties of an acid-additive is critical
for enantiocontrol
Photoinduced, Palladium-Catalyzed Enantioselective 1,2-Alkylsulfonylation of 1,3-Dienes
No full textThe
chiral allylic sulfonylated group is a unique structural motif
embedded in a range of natural products and pharmaceuticals. Notably,
the synthesis of structurally diverse chiral allylic sulfonylated
derivatives via alkylsulfonylation of 1,3-dienes remains underexplored
because of its inherent challenges in stereocontrol and regioselectivity.
Herein, photoinduced, palladium-catalyzed enantioselective 1,2-alkylsulfonylation
of conjugated 1,3-dienes is described. A wide variety of alkyl bromides,
1,3-dienes, and sodium sulfinates could be facilely coupled to generate
value-added chiral allylic sulfonylated derivatives with high enantioselectivity.
Finally, the utility of this enantioselective difunctionalization
protocol was demonstrated in pharmaceutical analogue synthesis
The rearrangement of alkylallenes to 1,3-dienes
No full text1,3-Dienes are vital building blocks in organic synthesis. They underpin many fundamental synthetic transformations and are present in numerous natural products and drug candidate molecules. The rearrangement of an alkylallene to a 1,3-diene is an atom efficient, redox neutral, transformation that provides a straightforward synthetic route to functionalized 1,3-dienes. Herein, we provide an account of this transformation using allenes that are not predisposed by the presence of heteroatoms or electron-withdrawing groups directly attached to the allene. Early reports of this skeletal rearrangement are acid-mediated approaches, with limited substrate scope, but they provide valuable mechanistic insights. More recent transition metal-mediated approaches that exhibit improved substrate scope are described, together with isolated examples that have utilized this rearrangement
Cu-Catalyzed Enantioselective Protoboration of 2,3-Disubstituted 1,3-Dienes
No full textA Cu-catalyzed
regio- and
enantioselective protoboration of 2,3-disubstituted 1,3-dienes is
described. The protocol operates under mild conditions and is applicable
to symmetrically and unsymmetrically substituted dienes, providing
access to homoallylic boronates in consistently high yield, regioselectivity,
and enantiomeric ratio. Preliminary investigations point to a complex
mechanism
- …
